:root {
  --bg: #0d1016;
  --surface: #131823;
  --surface-2: #0b111b;
  --ink: #e8ecf3;
  --muted: #a6b1c1;
  --dim: #758095;
  --line: #273142;
  --grid: rgba(120, 150, 210, .07);
  --accent: #4be08f;
  --display: "Bricolage Grotesque", "Avenir Next", "Segoe UI", sans-serif;
  --body: "Geist", "Helvetica Neue", Arial, sans-serif;
  --mono: "Geist Mono", ui-monospace, "SF Mono", Menlo, monospace;
  color-scheme: dark;
}
@media (prefers-color-scheme: light) {
  :root {
    --bg: #eef1f6; --surface: #f8faff; --surface-2: #e8edf5;
    --ink: #10141c; --muted: #4a5466; --dim: #67758a;
    --line: #cdd4df; --grid: rgba(40, 80, 160, .08); --accent: #12854a;
    color-scheme: light;
  }
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
html, body { margin: 0; min-height: 100%; }
body.book-page { background: var(--bg); color: var(--ink); font: 400 16px/1.6 var(--body); -webkit-font-smoothing: antialiased; }
a { color: inherit; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 4px; }
[id] { scroll-margin-top: 86px; }
.wrap { max-width: 1180px; margin-inline: auto; padding-inline: clamp(16px, 4vw, 40px); }

/* Shared site navigation */
.nav { position: sticky; top: env(safe-area-inset-top, 0px); z-index: 30; background: color-mix(in srgb, var(--bg) 82%, transparent); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-bottom: 1px solid var(--line); }
.nav .wrap { display: flex; align-items: center; gap: 24px; height: 60px; }
.mark { font: 800 20px/1 var(--display); letter-spacing: .14em; text-decoration: none; display: flex; align-items: center; gap: 10px; }
.mark svg { width: 26px; height: 26px; }
.nav ul { list-style: none; display: flex; gap: 22px; margin: 0 0 0 auto; padding: 0; }
.nav ul a { font: 500 13px/1 var(--mono); letter-spacing: .06em; text-transform: uppercase; color: var(--muted); text-decoration: none; }
.nav ul a:hover, .nav ul a.active { color: var(--ink); }
.cv-btn { font: 500 13px/1 var(--mono); letter-spacing: .06em; text-decoration: none; padding: 9px 14px; border: 1px solid var(--line); border-radius: 999px; color: var(--ink); }
.cv-btn:hover { border-color: var(--accent); color: var(--accent); }
.mobile-nav { display: none; }
@media (max-width: 760px) {
  .nav ul { display: none; }
  .mobile-nav { display: block; margin-left: auto; position: relative; }
  .mobile-nav summary { list-style: none; cursor: pointer; font: 500 13px/1 var(--mono); letter-spacing: .06em; text-transform: uppercase; padding: 10px 12px; border: 1px solid var(--line); border-radius: 999px; }
  .mobile-nav summary::-webkit-details-marker { display: none; }
  .mobile-nav[open] summary { border-color: var(--accent); }
  .mobile-links { position: absolute; right: 0; top: calc(100% + 10px); display: grid; width: 190px; padding: 8px; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; box-shadow: 0 18px 48px rgba(0,0,0,.3); }
  .mobile-links a { display: block; padding: 11px 12px; color: var(--ink); font: 500 14px/1.2 var(--body); text-decoration: none; border-radius: 7px; }
  .mobile-links a:hover, .mobile-links a.active { background: var(--surface-2); }
}

/* Book entrance */
.book-hero, .book-route-head { background-image: linear-gradient(var(--grid) 1px, transparent 1px), linear-gradient(90deg, var(--grid) 1px, transparent 1px); background-size: 32px 32px; border-bottom: 1px solid var(--line); }
.book-hero .wrap { display: grid; grid-template-columns: minmax(0, 1fr) minmax(180px, 260px); gap: clamp(28px, 6vw, 88px); align-items: center; padding-block: clamp(54px, 7vw, 88px); }
.eyebrow { font: 500 12px/1 var(--mono); letter-spacing: .12em; text-transform: uppercase; color: var(--dim); display: flex; gap: 10px; align-items: center; }
.eyebrow::before { content: ""; width: 18px; height: 1px; background: currentColor; }
.book-hero h1 { max-width: 850px; margin: 22px 0 20px; color: var(--ink); font: 800 clamp(48px, 5.7vw, 76px)/.98 var(--display); letter-spacing: -.045em; text-wrap: balance; }
.book-hero p { max-width: 57ch; margin: 0; color: var(--muted); font-size: clamp(17px, 1.7vw, 19px); line-height: 1.55; }
.book-hero .actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 28px; }
.book-hero .btn { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: 12px 19px; border: 1px solid var(--line); border-radius: 999px; color: var(--ink); font: 500 14px/1 var(--body); text-decoration: none; }
.book-hero .btn.primary { background: var(--accent); border-color: var(--accent); color: var(--bg); }
.book-hero .btn:hover { border-color: var(--accent); }
.book-cover { width: 100%; max-height: 365px; object-fit: cover; object-position: 50% 47%; border: 1px solid var(--line); border-radius: 14px; box-shadow: 0 35px 70px -25px rgba(0,0,0,.65); }
.book-route-head .wrap { display: flex; gap: 12px; align-items: center; padding-block: 28px; color: var(--dim); font: 500 12px/1.4 var(--mono); letter-spacing: .1em; text-transform: uppercase; }
.book-route-head a { color: var(--accent); text-decoration: none; }
.book-route-head a:hover { text-decoration: underline; }

/* Contents and reading surface */
.book-shell { display: grid; grid-template-columns: 258px minmax(0, 1fr); gap: clamp(24px, 4vw, 48px); max-width: 1180px; margin-inline: auto; padding: clamp(32px, 5vw, 64px) clamp(16px, 4vw, 40px) 100px; }
.book-sidebar { min-width: 0; position: sticky; top: 84px; align-self: start; padding: 22px 18px; border: 1px solid var(--line); border-radius: 16px; background: var(--surface); }
.book-sidebar-title { margin-bottom: 16px; font: 800 22px/1.1 var(--display); letter-spacing: -.02em; color: var(--ink); }
.book-sidebar-toggle { display: none; }
.book-chapter-list { display: grid; gap: 4px; }
.book-chapter { min-width: 0; }
.book-chapter summary { list-style: none; display: flex; align-items: flex-start; gap: 8px; min-height: 38px; padding: 9px 8px; color: var(--muted); cursor: pointer; font: 600 13px/1.4 var(--mono); }
.book-chapter summary::-webkit-details-marker { display: none; }
.book-chapter summary::before { content: "+"; flex: 0 0 12px; color: var(--accent); font: 500 16px/1 var(--mono); }
.book-chapter[open] summary::before { content: "−"; }
.book-chapter[open] summary, .book-chapter.is-current summary, .book-chapter summary:hover { color: var(--ink); }
.book-section-list { display: grid; gap: 0; margin: 0 0 8px 13px; padding-left: 13px; border-left: 1px solid var(--line); }
.book-section-list a { display: block; padding: 6px 0; color: var(--muted); text-decoration: none; font: 400 13px/1.4 var(--body); }
.book-section-list a:hover, .book-section-list a.active { color: var(--accent); }
.book-support { display: grid; gap: 10px; margin-top: 18px; padding-top: 20px; border-top: 1px solid var(--line); }
.book-support-title { color: var(--ink); font: 700 16px/1.2 var(--display); }
.book-support p { margin: 0; color: var(--muted); font: 400 13px/1.5 var(--body); }
.book-support-button { display: inline-flex; justify-content: center; align-items: center; min-height: 40px; padding: 9px 12px; border: 1px solid var(--accent); border-radius: 999px; background: var(--accent); color: var(--bg) !important; font: 600 13px/1 var(--body); text-decoration: none; }
.book-social-links { display: flex; gap: 7px; }
.book-social-link { display: inline-flex; align-items: center; justify-content: center; width: 36px; height: 36px; border: 1px solid var(--line); border-radius: 8px; color: var(--muted) !important; text-decoration: none; }
.book-social-link:hover { border-color: var(--accent); color: var(--accent) !important; }
.book-social-link svg { width: 17px; height: 17px; fill: currentColor; }

.book-content.c64 { width: 100%; min-width: 0; max-width: none; min-height: 65vh; margin: 0; padding: clamp(24px, 4.5vw, 60px); border: 1px solid var(--line); border-radius: 18px; background: var(--surface); box-shadow: 0 26px 75px -58px rgba(0,0,0,.75); }
.book-content, .book-content p, .book-content li, .book-content td, .book-content th { color: var(--muted) !important; }
.book-content p, .book-content li { margin-block: 0 1.35em !important; font: 400 17px/1.78 var(--body) !important; overflow-wrap: anywhere; }
.book-content p > span, .book-content li > span { color: inherit !important; font-family: inherit !important; font-size: inherit !important; line-height: inherit !important; }
.book-content h1, .book-content h2, .book-content h3, .book-content h4, .book-content h5, .book-content h6 { color: var(--ink) !important; background: transparent !important; text-align: left !important; }
.book-content h1 span, .book-content h2 span, .book-content h3 span, .book-content h4 span { color: inherit !important; font-family: inherit !important; font-size: inherit !important; font-weight: inherit !important; line-height: inherit !important; }
.book-content h2 { margin: 0 0 36px !important; padding: 0 !important; font: 800 clamp(35px, 4vw, 54px)/1.08 var(--display) !important; letter-spacing: -.03em !important; }
.book-content h3 { margin: 50px 0 20px !important; padding: 0 0 12px !important; border-bottom: 1px solid var(--line); font: 700 clamp(25px, 2.6vw, 33px)/1.2 var(--display) !important; letter-spacing: -.02em !important; }
.book-content > h3:first-child { margin-top: 0 !important; }
.book-content h4 { margin: 30px 0 14px !important; font: 700 22px/1.3 var(--display) !important; }
.book-content p, .book-content span, .book-content li, .book-content [style*="background"] { background-color: transparent !important; }
.book-content p.c9 { display: none !important; }
.book-content a, .book-content a span { color: var(--accent) !important; text-underline-offset: 3px; }
.book-content a:hover { text-decoration: underline; }
.book-content ul, .book-content ol { padding-left: 22px; }
.book-content table { width: 100% !important; max-width: 100% !important; table-layout: auto; border-collapse: separate; border-spacing: 0; margin: 26px 0 !important; border: 1px solid var(--line); border-radius: 10px; }
.book-content td, .book-content th { min-width: 0; padding: 14px !important; border: 0 !important; border-right: 1px solid var(--line) !important; border-bottom: 1px solid var(--line) !important; background: var(--surface-2) !important; vertical-align: middle !important; }
.book-content tr > :last-child { border-right: 0 !important; }
.book-content tr:last-child > * { border-bottom: 0 !important; }
.book-content td p { font-size: 15px !important; line-height: 1.55 !important; margin: 0 !important; }
.book-content td span { background: transparent !important; }
.book-content img { display: block !important; max-width: 100% !important; height: auto !important; margin-inline: auto !important; }
.book-content span:has(> img) { display: flex !important; align-items: center !important; justify-content: center !important; width: auto !important; max-width: 100% !important; height: auto !important; overflow: visible !important; }
.book-content .book-media-table { display: block; overflow-x: auto; }
.book-content .book-media-table tbody { display: table; width: 100%; table-layout: fixed; }
.book-content .book-media-table td { text-align: center !important; }
.book-content .book-media-table td p { text-align: center !important; }
.book-content .book-note-table td { text-align: left !important; }
.book-content .book-example { margin: 28px 0; max-width: 100%; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; background: #090f18; }
.book-content .book-example-body { display: grid; grid-template-columns: minmax(0, 1fr); }
.book-content .book-example-code, .book-content .book-example-result { min-width: 0; }
.book-content .book-example-result { border-top: 1px solid var(--line); background: var(--surface-2); }
.book-content .book-example-bar { display: flex; align-items: center; justify-content: space-between; gap: 12px; min-height: 39px; padding: 9px 16px; border-bottom: 1px solid var(--line); color: #93a7bc !important; font: 500 11px/1.3 var(--mono); letter-spacing: .08em; text-transform: uppercase; }
.book-content .book-copy { flex: none; padding: 3px 0; border: 0; background: none; color: #77d8aa; font: inherit; letter-spacing: inherit; cursor: pointer; text-transform: uppercase; }
.book-content .book-copy:hover { color: #b3f5d0; }
.book-content .book-code { display: block; max-width: 100%; margin: 0; padding: 17px 18px 20px; overflow-x: auto; color: #dce8ed !important; font: 400 13px/1.6 var(--mono); white-space: pre; tab-size: 2; }
.book-content .book-code code { font: inherit; }
.book-content .book-code span { font: inherit !important; background: transparent !important; }
.book-content .book-code .token-keyword { color: #6fe1a1 !important; }
.book-content .book-code .token-type { color: #81d5e9 !important; }
.book-content .book-code .token-number { color: #f2bc7d !important; }
.book-content .book-code .token-string { color: #e9b2a3 !important; }
.book-content .book-code .token-comment { color: #8294a9 !important; }
.book-content .book-code .token-function { color: #c5adf7 !important; }
.book-content .book-code .token-annotation { color: #f1d58c !important; }
.book-content .book-result-body { display: flex; flex-direction: column; justify-content: center; align-items: center; gap: 8px; min-height: 130px; padding: 18px; text-align: center; }
.book-content .book-result-body p { margin: 0 !important; font-size: 13px !important; text-align: center !important; }
.book-content .book-result-body img { width: auto !important; max-width: 100% !important; max-height: 340px !important; object-fit: contain; }
.book-content .book-callout { display: grid; grid-template-columns: 36px minmax(0, 1fr); align-items: start; gap: 14px; margin: 26px 0; padding: 16px 19px; border: 1px solid color-mix(in srgb, var(--accent) 35%, var(--line)); border-left: 3px solid var(--accent); border-radius: 10px; background: color-mix(in srgb, var(--accent) 5%, var(--surface-2)); }
.book-content .book-callout-icon { display: flex; align-items: center; justify-content: center; width: 36px; min-height: 36px; }
.book-content .book-callout-icon img { max-width: 32px !important; max-height: 32px !important; }
.book-content .book-callout-text p { margin: 0 !important; font-size: 15px !important; line-height: 1.65 !important; }
.book-content .book-callout-text p + p { margin-top: 10px !important; }
.chapter-pager { display: flex; justify-content: space-between; gap: 12px; margin-top: 56px; padding-top: 26px; border-top: 1px solid var(--line); }
.chapter-step { min-height: 44px; display: inline-flex; align-items: center; padding: 11px 16px; border: 1px solid var(--line); border-radius: 999px; color: var(--muted) !important; font: 500 13px/1.3 var(--body); text-decoration: none; }
.chapter-step.primary { border-color: var(--accent); background: var(--accent); color: var(--bg) !important; }
.chapter-step:hover { border-color: var(--accent); }
.book-footer { border-top: 1px solid var(--line); padding: 28px 0; color: var(--dim); font: 400 12px/1.5 var(--mono); }
.book-footer .wrap { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; }
.book-footer a { color: var(--muted); text-decoration: none; }

@media (max-width: 900px) {
  .book-shell { grid-template-columns: minmax(0,1fr); }
  .book-sidebar { position: static; }
  .book-sidebar-title { display: flex; align-items: center; justify-content: space-between; margin: 0; }
  .book-sidebar-toggle { display: inline-flex; align-items: center; justify-content: center; min-height: 36px; padding: 8px 12px; border: 1px solid var(--line); border-radius: 999px; background: transparent; color: var(--ink); font: 500 12px/1 var(--mono); cursor: pointer; }
  .book-sidebar:not(.toc-open) .book-chapter-list, .book-sidebar:not(.toc-open) .book-support { display: none; }
  .book-sidebar.toc-open .book-chapter-list { margin-top: 18px; }
  .book-hero .wrap { grid-template-columns: minmax(0, 1fr) 180px; }
}
@media (max-width: 640px) {
  .book-hero .wrap { grid-template-columns: minmax(0,1fr); }
  .book-hero h1 { font-size: clamp(44px, 12vw, 61px); }
  .book-cover { width: 160px; max-height: 225px; justify-self: start; }
  .book-content.c64 { padding: 24px 18px; }
  .book-content h3 { margin-top: 38px !important; }
  .book-content .book-media-table tbody { min-width: 490px; }
  .book-content .book-code { font-size: 12px; }
  .chapter-pager { display: grid; }
}